Container and method of making same

ABSTRACT

A reinforced fiberboard container having a plurality of reinforcing pads adhesively attached to its vertical sidewalls. Each reinforcing pad has a height substantially less than the height of the attached sidewall, and the method of adhesive attachment is such that sidewalls of the container are bowed inward in a region vertically adjacent the reinforcing pads. When the container is made of outer and inner units, the pads are preferably disposed between the sidewalls of the units but may also be located on the inner surface of the inner unit. When the reinforcing pads are to be located adjacent the upper and/or lower edges of the sidewalls, sidewall extensions may be provided which can be folded upward or downward to create the pads.

United States Patent Wood [451 Apr. 4, 1972 [54] CONTAINER AND METHOD OF MAKING SAME Primary Examiner-James Marbert Attorney-Fitch, Even, Tabm & Luedeka [72] lnventor: Robert N. Wood, Indianapolis, lnd.

[73] Assignee: Inland Container Corporation, lndi- [57] v ABSTRACT anapollsi A reinforced fiberboard container having a plurality of rein- [22] Filed: 29, 1969 forcing pads adhesively attached to its vertical sidewalls. Each reinforcing pad has aheight substantially less than the height [21] Appl. No.: 888,570 of the attached sidewall, and the method of adhesive attachment is such that sidewalls of the container are bowed inward in a region vertically adjacent the reinforcing pads, (g1 when the container is made of outer and inner uni. the pads 58] Fie'ld 23 C are preferably disposed between the sidewalls of the units but may also be located on the inner surface of the inner unit. When the reinforcing pads are to be located adjacent the [56] References Cited upper and/or lower edges of the sidewalls, sidewall extensions UNITED STATES PATENTS may be provided which can be folded upward or downward to create the pads. 2,729,384 1/1956 George et a1 ..229/23 B 3,010,633 1 1/1961 Reher ..229/23 BT 22 Claims, 8 Drawing Figures i I I b I. y I 2 1 v a A t4 v S i. t? s 1 $2 e as 5; I r so so I it? m \s w =.'-,.,,:;;;:,',-;,1,-,'; 2;-,;

Patented April 4, 1972 3,653,578

2 Sheets-Sheet 1 FIG.I

== V r32 1 How CONTAINER AND METHOD OF MAKING SAME This invention relates to fiberboard containers formed from folded blanks and more particularly to such fiberboard containers which are adapted for the shipment of bulk, flowable materials.

Bulk flowable materials, such as synthetic resins, crude or synthetic rubber, viscous liquid materials, frozen foods and the like, have a substantial weight per unit volume. In order to utilize the fiberboard containers for the shipment of these materials, various specialized containers have been developed, some of which have employed multi-cell arrangements to increase strength and decrease sidewall bulging. Bulging results in a loss of resistance in the container wall to top load compression and in possible failure of the wall when containers are stacked one atop another. Various other means have been also employed for reinforcing the outer walls to prevent bulging of the containers.

Early attempts, such as shown in U.S..Pat. No. 2,036,987, utilized pairs of stay wires extending transversely across containers between opposite sidewalls, together with metallic end frames, in order to provide both vertical strength and bulge resistance. Other arrangements, such as shown in U.S. Pat. No. 2,762,551, utilized telescoping sleeves of coextensive heights together with metal bands which circumscribed the closed containers from top to bottom. Later attempts, such as that shown in U.S. Pat. No. 3,010,633, employed such telescoping sleeves together with vertical paperboard bands which encircled the innermost tubular sleeve placing it under tension. More recently, U.S. Pat. No. 3,306,517 disclosed a reinforced container wherein the vertical bands were applied in sections to the individual panels and flaps prior to setting-up and closing of the container.

None of these previous attempts have been completely satisfactory inasmuch as they have variously required relatively large additions of fiberboard materials, have included reinforcing elements which interferred with access to the entrance through which the container would be filled, or have not truly provided sufficient additional strength in the container to justify the inclusion thereof. Accordingly, improved versions of reinforced containers of this general type are desired.

An object of the present invention is to provide an improved fiberboard container which is reinforced to provide good stacking strength. Another object of the invention is to provide a method for making a reinforced fiberboard container suitable for holding bulk flowable material of any aggregate size or any bulk material with cold flow properties which has improved structural strength in resisting vertical compression. A further object of the invention is to provide improved reinforced fiberboard containers made from folded fiberboard blanks which containers utilize little more fiberboard than nonreinforced containers of this same size.

These and other objects of the invention should be apparent from the following detailed description of containers embodying various features of the invention when read in conjunction with the accompanying drawings wherein:

FIG. I is a perspective view, with portions broken away, of a fiberboard container embodying various features of the inventron;

FIG. 2 is an enlarged sectional view of the container shown in FIG. 1, taken generally along the line 22;

FIG. 3 is a plan view of a fiberboard blank of the type employed to form the container depicted in FIG. 1;

FIG. 4 is a diagrammatic view illustrating the method of making the composite blank for the container shown in FIG. 1;

FIG. 5 is a plan view of an alternative embodiment of a container blank generally similar to that shown in FIG. 3;

FIG. 6 is a vertical sectional view through a container formed from the blank shown in FIG. 5;

FIG. 7 is a plan view of another alternative embodiment of a container blank similar to that shown in FIG. 3; and

FIG. 8 is a vertical sectional view through a container formed from the blank shown in FIG. 7.

It has been found that significantly increased bulge resistance and stacking strength is provided in a fiberboard container if the container is constructed in a manner to originally create a bow in the sidewalls. By the proper placement of reinforcing panels of a size less than the height of the container sidewalls, the outer sidewalls of the containers can be caused to bow inward, and under some circumstances, the vertical cross-section of the overall sidewalls can be caused to take an A-frame shape. Such reinforcing panels properly placed can provide as much as a 50 percent increase in the bulge-resistance strength of the container while the panels themselves require an amount of fiberboard material which is only a minor portion of the material constituting the container sidewalls.

Illustrated in FIG. 1 is a folded blank container II which includes an inner box 13, which has a bottom closure of a regular slotted container (RSC) and 2 flanged upper end, and surrounding outer tube or sleeve 15. The inner box 13 is rectangular in cross-section, having four sidewalls provided by side panels 17 and 18 and end panels 19 and 20, each of which have attached bottom flaps 23 and top flanges 25. The container 11 is designed for employment with an interlocking cover 29; however, a tray-type cover or an RSC-style top closure or any other suitable top closure could be used. The blank for the inner box 13 is provided with a vertical tab 31 which in the illustrated version is hingedly attached along a score line to the side panel 18 and fastened to the interior surface of the end panel 19 by stitching or the like. The tab 31 may be hinged to the end panel 19 instead of to the side panel 18, and may be located at any other comer if desired. A taped joint may also be employed instead of such a lap joint. A butt joint may also be used on the inner box, and such joint may also be located at a comer other than that at which the outer tube joint is located. Likewise, the container arrangement may be reversed so that the tube is disposed interior of the slotted box, and when this is the case, it may be desirable to locate the tab 31 outside of the box instead of inside as in illustrated arrangement. The inner and outer units may have full, partial or no flaps, as may be desired.

The outer tube 15 includes four rectangular panels which are referred to as side panels 33 and end panels 35 with an extension tab 37 hinged along a score line to one end panel 35. The extension tab 37 is suitably fastened to the adjacent side panel 33 by the gluing, with the tab 37 lying outside the side panel 33. A taped joint could also be used.

Four reinforcing pads 39 are employed which are glued in place between the respective sidewalls of the inner box 13 and outer tube 15 which form the container 11. Each of the reinforcing pads 39 has a height equal to about one-quarter the height of the container sidewalls. The length of each of the pads 39 is slightly less than the corresponding dimension of the sidewall of the inner box 13 to which it is secured. The reinforcing pads 39 are adhesively attached, as by gluing, along both of their surfaces to the respective sidewalls of the inner box 13 and outer tube 15 with which they are in contact In addition to gluing both surfaces of the pads 39 to the adjacent surfaces of the sidewalls, each of the sidewalls of the inner box 13 and the outer tube 15 is glued at least across the major portion of its surface area, and preferably across its entire surface, to the adjacent surface of the adjacent sidewall. It is the gluing in this manner and the application of compression to the sidewalls in a transverse direction while the glue sets that creates the inward bowing that is desired.

The reinforcing pads 39 may be made of any suitable material which has a substantial thickness, so that the desired inward bowing is created at a location adjacent the upper or lower edge of the pad, and which has appreciable rigidity. Although materials such as wood and hardboard may be employed, usually less expensive materials, such as corrugated fiberboard and chipboard, are employed. In general, it is preferred to employ reinforcing pads 39 made of double faced corrugated or double-wall corrugated, although pads of single faced corrugated may also be used. If the inner box 13 and outer tube are made of corrugated board, for example single wall or double-wall corrugated, the flutes of the corrugating media in the box 13 and tube 15 will normally run in a vertical direction. When this is the case, it is preferable that the flutes in corrugated fiberboard reinforcing pads 39 run perpendicular to this direction, or in this instance horizontally. Likewise, the pads 39 may be extensions of either the inner or outer units if desired, and when this is the case, these extensions will be located at the top and/or bottom of the units.

In addition to creating the desirable inward bow in the sidewalls of the container 11, the reinforcing pads 39, when properly proportioned, also enhance the squarability of the container 11 by increasing the rigidity of the four comers. This effect is accomplished by proportioning the reinforcing pads 39 so that the length of each is slightly less than the respective dimension of the sidewalls of the inner box 13. As a result, there is some space provided between the ends of adjacent pads 39 into which the corners of the box can fold; and, when the container 11 is set up, the edges of the reinforcing pads 39 squeeze the corners of the inner box together with a rigidifying effect. In this respect, the reinforcing pad 39 is preferably proportioned to provide a gap at each end about equal to the thickness of the fiberboard material from which the sidewalls of the inner box 13 are made. For example, if G B flute double-wall corrugated is employed for the inner box 13 and the side panels 17 and 18 of the inner box each measure 42 inches in length, the reinforcing pads 39 which are used may have a length of about 41 Winches and should be centered with respect to the side .edges of the side panels 17 and 18.

The vertical location of the reinforcing pads 39 varies depending upon the characteristics it is desired to provide in the container 11. In the illustrated embodiment of the container ll, the reinforcing pads 39 are located adjacent bottom edges of the sidewalls of the container ll. Also, in the illustrated embodiment, the reinforcing pads are shown having a height equal to about 25 percent of the height of the container. It has been found that such pads located in this manner, so as to create an inward bow in the outside sidewalls, substantially increase the bulge resistance which the container ll exhibits when filled with bulk flowable materials.

Although preferably the reinforcing pads 39 are disposed between the sidewalls of the outer tube 15 and the inner box 13, where the pads are fully enveloped by the sidewalls, the desirable inward bowing of the outside sidewalls of the container may also be achieved if the reinforcing pads 39 are glued to the inside surfaces of the sidewalls of the inner box 13. Accordingly, if placement of the reinforcing pads 39 in such an exposed location that does not interfere with the loading or unloading of the container, the pads 39 may be glued only along one surface thereof to the inside surface of the inner box sidewalls l7, l8, l9 and 20, so long as the respective sidewalls of the inner box 13 and outertube 15 are glued together under compression in a manner to create the desired inward bow in the outside sidewalls.

FIG. 4 diagrammatically illustrates one suitable method for fabrication of the container 11. In this method, the four reinforcing pads 39 are preferably initially glued in place on the outside surfaces of the four sidewalls l7, l8, l9 and 20 of the inner box 13, and, if desired, the joint may be made at the comer between the extension tab 31 and the end panel 19. Then the inside surfaces of the four panels of the outer tube 15 are coated with glue, and the tube blank is appropriately disposed adjacent the inner box blank. In the illustrated embodiment, the juxtaposed blanks are folded along diagonally opposite corners of the container II which do not include the jointed corner.

Compression is then applied in a transverse direction, as indicated by the arrows in FIG. 4, to laminate one blank to the other. During the compression, the inner surface of the blank for the inner box 13 lies along an imaginary central plane, and the remainder of the juxtaposed blanks are deformed approximately to the cross-sectional shape illustrated. While the transverse compression is being applied, the inside surfaces of sidewalls of the inner box l3 remain substantially flat, lying along the central imaginary plane whereas the side panels 33 and end panels 35 of the outer tube 15 are bowed toward this plane at the regions illustrated, i.e., adjacent the upper edges of the reinforcing pads 39. The compression may be applied in any suitable manner as is well known in the art, and it should be maintained until the glue has set.

When the compression is released, the inherent character of the corrugated fiberboard from which the blanks are made exhibits some tendency to return to its original shape where the flutes are straight. The effect of this tendency is to somewhat lessen the inward bow in the sidewalls of the outer tube 15 and to consequently create a slight bow in the sidewalls of the inner box 13, as seen in FIG. 2. Thus, when the reinforcing pads 39 are glued between the sidewalls of the inner box 13 and outertube 15, the sidewalls of the finished container 11 exhibit the A-frame cross-sectional shape to which reference was previously made.

As previously indicated, the height of the reinforcing pads 39 is less than half the height of the container sidewalls, and preferably, the individual reinforcing pads 39 are between about 15 and 35 percent of the height of the container sidewalls. Although a substantial improvement in bulge resistance is provided when pads 39 equal to about 15 percent of the height of the sidewalls are employed, the improvement increases as the height of the pads increase. However, the rate of increase of the bulge resistance is not constant. Accordingly, pads 39 having a height greater than about 35 percent of the height of the container 11 are generally not employed because further increases in the height of the reinforcing pads 39 results in only relatively small increments of increase in bulge resistance.

The location of the reinforcing pads 39 is important in achieving the desired objectives in strength improvement in the resultant containers. Depending upon the flow characteristics of the product to be packaged in the container and the density of the product, it may be desirable to employ pads near the bottom of the container 11, as illustrated in the construction shown in FIGS. 1 through 4.. However, if stacking strength is of major importance to permit the filled containers to be supported one atop another, it is often desirable to locate reinforcing pads near the tops of the container sidewalls, as illustrated in FIGS. 5 and 6. It has been found that the strategic placement of reinforcing pads near the tops of the container sidewalls provides reinforcement at locations where substantial stresses are created in container sidewalls when such containers are stacked one atop another.

FIGS. 5 and 6 illustrate a container 51 which is made up of an inner tube 53 and an outer surrounding box 55 having a regular slotted bottom closure and a flanged top. The sidewalls of the inner tube 53 are formed by side panels 57 and end panels 59 and are formed into the tubular structure via a stitched joint using the extension tab 60 hinged to a side panel 57. The outer box 55 is formed from a folded blank having side panels 61 and end panels 63, each of which is provided which hinged upper flanges 65 and lower bottom flaps 67. Four reinforcing pads 69 are glued to the inside surface of the inner tube 53. The reinforcing pads 69 are generally similar in dimensions to the pads 39 which were employed in the container 11, extending not quite into the comers, and they are preferably made from double faced corrugated fiberboard with the flutes running horizontally.

When the reinforcing pads 69 are located generally adjacent the top edge of the sidewalls, an inward bow in the sidewalls is created immediately veritically below the lower edge of the pads 69. It has been found that, in the stacking of one container atop another, a concentration of stresses is created in the upper regions of the container 51 sidewalls. The disposition of the reinforcing pads 69 in corresponding locations has been found to provide increased resistance to bulging in the sidewalls of stacked containers. Accordingly, the inclusion of reinforcing pads 69 in these locations so increases its strength that a container which previously would not have been rated for use in stacked configuration now exhibits sufficient bulge resistance when stacked to permit it to be so rated.

In FIGS. 7 and 8 are shown a container 71 which is provided with reinforcements to increase its bulge resistance both from the standpoint of containing a flowable, relatively dense bulk material, such as synthetic rubber, and from the standpoint of stackability. The container 71 includes an inner unit 73, which in this case is only a tube, and an outer surrounding unit or tube 75. The container 71 is square in cross section. The inner unit 73 has four side panels 77 and is designed to be formed into a tubular structure by a taped joint. The outer tube has four side panels 83 which are formed into tubular configuration by a glued joint using an extension tab 85.

Disposed between the respective sidewalls of the outer tube 75 and the inner unit 73 are upper reinforcing pads 87, lower reinforcing pads 89 and a central reinforcing pad 91 in the form of a continuous strip. The upper and lower reinforcing pads 87 and 89 serve essentially the same functions as did the reinforcing pads 39 and 69, heretofore discussed. The lower pads 89 primarily provide increased bulge resistance in constraining the internal load within the container 71, and the upper pads 87 provide reinforcement in the regions where stresses are concentrated when containers of this type are stacked one atop another.

The employment of a central strip 91 as a reinforcing pad is considered especially suited for a container such as this designed to package a fairly dense, flowable material, such as synthetic rubber. Such a material exerts a substantial outward force on the sidewalls of the container 71 along a considerable distance vertically upward. Accordingly, whereas in com tainers for holding less dense or less flowable materials, reinforcing pads 89 located near the bottom of the container sidewalls provide sufficient reinforcement, for containers designed to hold a material such as synthetic rubber, a second region of reinforcement generally vertically centrally of the sidewalls has been found desirable. The squareness of the corners of the containers 71 in the central region is not as important as is squareness near the top and bottom of the container 71, and therefore the continuous strip 91 may be employed instead of separate reinforcing pads. To also provide stacking strength in the container 71, a zone of upper reinforcement is established by the inclusion of the upper pads 87.

In the container 71, each of the individual reinforcing pads is generally about the same height, and usually each individually measures about to percent of the height of the overall sidewall. it has been found that containers 71 made of double-wall corrugated fiberboard and having reinforcing pads 87, 89 and 91 of single wall corrugated made in accordance with this general construction can individually hold as much as 2,200 pounds of synthetic rubber and can be stacked in two-high configurations.

As best seen in FIG. 8, bottom flaps 93 to form a bottom closure for the container 71 are provided by extensions of the lower reinforcing pads 89. In a container of this type, the primary strength requirements occur in the sidewalls of the inner unit 73 and the outer unit 75, and double-wall corrugated fiberboard may be used herein. By forming the bottom flaps 93 as extensions of the lower reinforcing pads 89, the flaps 93 can be made of single wall corrugated, which provides adequate strength at less expense than double-wall corrugated. Likewise, upper flaps or flanges may be included by forming the upper reinforcing pads 87 with similar extensions.

The following example is provided for purposes of illustration and should not be considered to constitute limitations upon the invention which is defined in the appended claims appearing at the end of this specification.

EXAMPLE A bulk packaging container is made for holding particulate synthetic resins having a density of about 40 pounds per cubic foot and a particle size less than about inch. The container is designed to hold 1,200 pounds of these synthetic resins and has a length of 41 inches, a width of 33 inches and a depth of 384% inches. The container is manufactured from two separate scored and slotted corrugated blanks which, when assembled and glued together, provide an inner unit or box having an RSC bottom and a flanged top which is surrounded by an outer tube of the same height. Disposed between each pair of adjacent sidewalls of the inner box and outer tube are four upper and four lower reinforcing pads, each of which have a height of about 7 inches. The upper pads are disposed with their upper edges located generally along the top edges of the container sidewalls, and the lower pads are likewise disposed with their lower edges generally adjacent the bottom edges of the container sidewalls.

The blanks for the inner box and for the outer tube are made from 500 lb. double-wall corrugated fiberboard having B-C flutes. The reinforcing pads are made from 275 lb. test, single wall corrugated fiberboard having C flutes. The flutes in the inner box and in the outer tube run vertically, whereas the flutes in the reinforcing pads run horizontally. The outer tube has a glued joint whereas the inner box has a taped joint, both of which are located at the same corner of the container. The reinforcing pads which are affixed to the outer surface of the side panels of the inner box each have a length of about 40- 1% inches, and the reinforcing pads affixed to the end panels have a length of about 32-% inches.

In manufacturing the composite blank for the container, the individual blanks for the outer tube and the inner box are first suitably cut, slotted and scored. Then glue is applied to one surface of the eight reinforcing pads, and they are appropriately located upon the outside surface of the inner box blank. Then the inside surface of the blank for the outer tube is coated with glue, and it is aligned with the inner box blank to sandwich the reinforcing pads therebetween. The composite blank is folded along the two vertical corner score lines which flank the comer where the outer joint is located, so that the jointed comer lies fiat. The folded composite blank is transversely compressed in a compression form wherein a pressure of about 50 psi. is exerted against the outer surfaces of the folded outer tube.

A coldset adhesive is used for the gluing operations. The pressure on the folded composite blank is maintained for a sufficient time for this adhesive to set. In the completed container structure, the strength of the adhesive is such that rupture of the fibers in he fiberboard will occur before the adhesive bond would be broken. Examination of the blank after the compression operation shows that the outer surfaces of the container sidewalls exhibit a distinct inward bow in the region vertically below the upper reinforcing pads and in the region vertically above the lower reinforcing pads. A similar bow, but of lesser magnitude, is present in the internal surfaces of the container sidewalls, thus providing the vertical cross section of the container walls with an A-frame shape. The joints are then made to unite the inner box blank and the outer tube blank into tubular structures. The composite box blanks are designed for shipment to the ultimate user in knockdown configuration, i.e., in the folded form in which the compression was applied.

When the container is ready to be used, the folded blank is set up, and the bottom closure is formed by gluing the outside surfaces of the bottom flaps, which are attached to the end panels to the inside surfaces of the bottom flaps which are attached to the side panels. The container is then filled with 1,200 pounds of synthetic resins, and it is ready for shipment after a standard interlocking cover is attached to the flanges at the upper end of the inner box. These containers loaded in this manner are rated for shipment stacked in a two-high configu ration, and they exhibit excellent performance in such applications.

By the employment of the reinforcing pads, containers are provided which can be shipped and stored in flat configuration and which, when filled with flowable bulk materials, will withstand stacking of two or more units high. The containers restrict bulging of the sidewalls through the strategic placement and adherence of reinforcing pads to the panels which form the container sidewalls. The inward bowing of the outer sidewall surfaces that is created unexpectedly provides substantial increases in the strength of the container. By the employment of such reinforcing pads, sidewall strength approaching that which would be provided by the inclusion of an entire additional tube can be obtained while using only a fraction of the fiberboard material such an additional tube would require. As previously indicated, the containers may be made of any suitable configuration, and both inner and outer tubes might be employed together with tray-type bottoms and caps. Alternatively, either or both of the inner and outer tubular constructions may be provided with flaps and/or flanges to integrally provide a top or bottom closure or to facilitate connection to such a closure. As also previously indicated, such flaps and/or flanges may be provided by extensions of the respective reinforcing pads located at the top or the bottom edges of the container.

Moreover, when it is desired to employ reinforcing pads either at the top edge or at the bottom edge of the sidewalls, such reinforcing pads may be made by providing extensions of the sidewalls of either the inner or outer units having the desired dimensions Such extensions are appropriately folded upward or downward to lie against the desired surface of the sidewall. Folding of such extensions is facilitated by cutting or scoring along the lines joining the extensions to the sidewalls, and preferably when corrugated fiberboard is used for the construction, slitting is employed to cut through at least the linerboard at one surface, leaving the linerboard at the opposite surface to act as a hinge for the fold. Provision of the reinforcing pads in this manner facilitates production because the pads are automatically positioned at their proper locations upon folding.

Various of the features of the invention are set forth in the claims which follow.

What is claimed is:

l. A reinforced fiberboard container having a plurality of interconnected vertical sidewalls which form an enclosure open at the top and bottom thereof, means for closing the bottom thereof, and'means for closing the top thereof, and having the improvement comprising reinforcing pad means adhesively attached to a plurality of said sidewalls and extending substantially horizontally thereof, said reinforcing pad means having a height substantially less tan the height of said attached sidewall, said sidewall of said container being bowed inward in a region vertically adjacent said substantially horizontally extending reinforcing pad means with the outer portion of said sidewall in said vertically adjacent region being displaced laterally inward of the outer portion of said sidewall in the region where said pad means is located.

2. A container in accordance with claim 1 wherein said enclosure is rectangular in cross-section and reinforcing pad means is attached to all four of said sidewalls.

3. A container in accordance with claim 1 wherein said reinforcing pad means has a height between about and 35 percent of the height of said sidewalls.

4. A container in accordance with claim 1 wherein the container includes two folded fiberboard blanks which form inner and outer tubular structures constituting said container sidewalls.

5. A container in accordance with claim 4 wherein said reinforcing pad means is disposed between said outer and inner tubular structures.

6. A container in accordance with claim 4 wherein said reinforcing pad means is adhesively attached to the inside surface of said inner tubular structure.

7. A container in accordance with claim 5 wherein said reinforcing pad means includes a plurality of separate pads each having a length equal to the length of said respective sidewall of said inner tubular structure less about twice the thickness of said fiberboard from which said inner structure is made.

A container in accordance with claim 5 wherein both the inner and outer portions of said sidewalls are bowed in the region vertically adjacent said reinforcing pad means to provide an A-frame cross-section.

9. A container in accordance with claim 1 wherein said reinforcing pad means is disposed generally adjacent the bottom edges of said sidewalls.

10. A container in accordance with claim 9 wherein said sidewalls are provided with bottom extension means which are folded upward to provide said reinforcing pad means.

11. A container in accordance with claim 9 wherein said reinforcing pad means is provided with lower extensions which form bottom flaps that provide said bottom closure means.

12. A container in accordance with claim 1 wherein said reinforcing pad means is disposed generally adjacent the upper edges of said sidewalls.

13. A container in accordance with claim 12 wherein said sidewalls are provided with upper extension means which are folded downward to provide said reinforcing pad means.

14. A container in accordance with claim 12 wherein said reinforcing pad means is provided with top extensions which extend above the upper edges of said sidewalls and cooperate in providing said top closure for said container.

15. A method of making a reinforced fiberboard container which method comprises providing a blank having a plurality of interconnected vertical sidewalls designed to form an enclosure open at the top and bottom thereof, adhesively attaching substantially horizontally extending reinforcing pad means to a plurality of said sidewalls, said reinforcing pad means having a height substantially less than the height of said sidewalls, and compressing said blank and said reinforcing pad means in a transverse direction to cause said sidewalls to be bowed inward in a region vertically adjacent said substantially horizontally extending reinforcing pad means with the outer portions of said sidewalls in said vertically adjacent regions being displaced laterally inward of the outer portions of said sidewalls in the region where said pad means is located.

16. A method in accordance with claim 15 wherein two of said fiberboard blanks are provided, and wherein the respective sidewalls of each are adhesively attached to form inner and outer tubular units constituting said enclosure.

17. A method in accordance with claim 16 wherein said reinforcing pad means is disposed between said outer and inner tubular units.

18. A method in accordance with claim 17 wherein said compressing is carried out while the adhesive bond between said respective sidewalls of said inner and outer units sets to cause both the inner and outer portions of said sidewalls to be bowed in the regions vertically adjacent said reinforcing panels and provide an A-frame cross-section.

19. A method in accordance with claim 15 wherein said reinforcing pad means is disposed generally adjacent the bottom edges of said sidewalls.

20. A method in accordance with claim 19 wherein said reinforcing pad means is formed by folding lower extensions of said sidewalls upward there adjacent 21. A method in accordance with claim 15 wherein said reinforcing pad means is disposed generally adjacent the upper edges of said sidewalls.

22. A method in accordance with claim 21 wherein said reinforcing pad means is formed by folding upper extensions of said vertical sidewalls downward there adjacent. 

1. A reinforced fiberboard container having a plurality of interconnected vertical sidewalls which form an enclosure open at the top and bottom thereof, means for closing the bottom thereof, and means for closing the top thereof, and having the improvement comprising reinforcing pad means adhesively attached to a plurality of said sidewalls and extending substantially horizontally thereof, said reinforcing pad means having a height substantially less tan the height of said attached sidewall, said sidewall of said container being bowed inward in a region vertically adjacent said substantially horizontally extending reinforcing pad means with the outer portion of said sidewall in said vertically adjacent region being displaced laterally inward of the outer portion of said sidewall in the region where said pad means is located.
 2. A container in accordance with claim 1 wherein said enclosure is rectangular in cross-section and reinforcing pad means is attached to all four of said sidewalls.
 3. A container in accordance with claim 1 wherein said reinforcing pad means has a height between about 15 and 35 percent of the height of said sidewalls.
 4. A container in accordance with claim 1 wherein the container includes two folded fiberboard blanks which form inner and outer tubular structures constituting said container sidewalls.
 5. A container in accordance with claim 4 wherein said reinforcing pad means is disposed between said outer and inner tubular structures.
 6. A container in accordance with claim 4 wherein said reinforcing pad means is adhesively attached to the inside surface of said inner tubular structure.
 7. A container in accordance with claim 5 wherein said reinforcing pad means includes a plurality of separate pads each having a length equal to the length of said respective sidewall of said inner tubular structure less about twice the thickness of said fiberboard from which said inner structure is made.
 8. A container in accordance with claim 5 wherein both the inner and outer portions of said sidewalls are bowed in the region vertically adjacent said reinforcing pad means to provide an A-frame cross-section.
 9. A container in accordance with claim 1 wherein said reinforcing pad means is disposed generally adjacent the bottom edges of said sidewalls.
 10. A container in accordance with claim 9 wherein said sidewalls are provided with bottom extension means which are folded upward to provide said reinforcing pad means.
 11. A container in accordance with claim 9 wherein said reinforcing pad means is provided with lower extensions which form bottom flaps that provide said bottom closure means.
 12. A container in accordance with claim 1 wherein said reinforcing pad means is disposed generally adjacent the upper edges of said sidewalls.
 13. A container in accordance with claim 12 wherein said sidewalls are provided with upper extension means which are folded downward to provide said reinforcing pad meaNs.
 14. A container in accordance with claim 12 wherein said reinforcing pad means is provided with top extensions which extend above the upper edges of said sidewalls and cooperate in providing said top closure for said container.
 15. A method of making a reinforced fiberboard container which method comprises providing a blank having a plurality of interconnected vertical sidewalls designed to form an enclosure open at the top and bottom thereof, adhesively attaching substantially horizontally extending reinforcing pad means to a plurality of said sidewalls, said reinforcing pad means having a height substantially less than the height of said sidewalls, and compressing said blank and said reinforcing pad means in a transverse direction to cause said sidewalls to be bowed inward in a region vertically adjacent said substantially horizontally extending reinforcing pad means with the outer portions of said sidewalls in said vertically adjacent regions being displaced laterally inward of the outer portions of said sidewalls in the region where said pad means is located.
 16. A method in accordance with claim 15 wherein two of said fiberboard blanks are provided, and wherein the respective sidewalls of each are adhesively attached to form inner and outer tubular units constituting said enclosure.
 17. A method in accordance with claim 16 wherein said reinforcing pad means is disposed between said outer and inner tubular units.
 18. A method in accordance with claim 17 wherein said compressing is carried out while the adhesive bond between said respective sidewalls of said inner and outer units sets to cause both the inner and outer portions of said sidewalls to be bowed in the regions vertically adjacent said reinforcing panels and provide an A-frame cross-section.
 19. A method in accordance with claim 15 wherein said reinforcing pad means is disposed generally adjacent the bottom edges of said sidewalls.
 20. A method in accordance with claim 19 wherein said reinforcing pad means is formed by folding lower extensions of said sidewalls upward there adjacent
 21. A method in accordance with claim 15 wherein said reinforcing pad means is disposed generally adjacent the upper edges of said sidewalls.
 22. A method in accordance with claim 21 wherein said reinforcing pad means is formed by folding upper extensions of said vertical sidewalls downward there adjacent. 